HUD bug

Steps to reproduce:

1. Complete any level other than level 14 (the last level)
2. Exit the level without clicking the next or previous buttons
3. Enter any level, and the next button in the bottom-right corner will still be there

This bug gives you the ability to skip levels or go to level 15 (which doesn't exist)

To go to level 15, you must have used the next button at least once. If you try to go to level 15 before doing this, it will just stay on level 14 with the transition never finishing. Because the transition never finished, the start button will not be able to be clicked until a different transition finishes.

Going to level 15 will also cause the launch sound to not play and launchable objects to not save their velocity.